Magnolia quichensis Tribouillier, A.Vázquez & Archila, 2022

Vázquez-García, J. Antonio, Tribouillier-Navas, Erick, Archila, Fredy, Aguilar, Rudy Eduardo & Shalisko, Viacheslav, 2022, Two new species of Magnolia (Magnoliaceae) from Alta Verapaz and Quiché, Guatemala, Phytotaxa 559 (1), pp. 35-44 : 37-39

Magnolia quichensis Tribouillier, A.Vázquez & Archila , sp. nov. ( Figs. 1–2 , 4 ).

Type — GUATEMALA. Quiché: municipality of Chajul, Amacchel , 1431 m, 15°40’N, 91°05’W, associated with Mortoniodendron pentagonum (Donnell-Smith) Miranda (1965: 29) , Quercus oocarpa Liebmann (1854: 184) , Amphitecna silvicola L.O. Williams (1976: 25) ; 15 May 2019 (fl, fr), Tribouillier & Archila MG-070 (holotype: BIGU ; isotypes: AGUAT!, BIGU!, IBUG!) .

Magnolia quichensis belongs to M. section Talauma Baillon (1866: 66) and is similar to M. steyermarkii , a species from Huehuetenango Department. It differs from the latter by its larger flowers up to 15.6 in diameter vs. 13 cm in M. steyermarkii , more numerous stamens 92–103 vs. 76, fewer carpels 22–28 vs. 30–32, longer spathaceous bracts 4.8–6.3 vs. 3.9 cm and longer sepals (6.1–)7–8 vs. 6.0 cm ( Table 1 ).

Evergreen trees, 7–22 m high, 45–70 cm DBH; stipules 4.1 × 1.1 cm, glabrous; petioles 6.00–8.10 × 0.37–0.50 cm, glabrous; leaves 19.0–29.3(–34.5) × 8.8–12.9(–15.0) cm, glabrous in both sides, broadly ovate to elliptic or oblongelliptic, base acute to obtuse, apex retuse to obtuse, number of secondary veins 8–10 (–11); floral peduncles glabrous, 6.20–8.90 × 0.70–0.85 cm, the mayor segment length 2.1–2.7 cm; spathaceous bracts 1, orbicular, glabrous on both sides, rigid, 4.8–6.3 × 6.4–8.7 cm; flowers 12.5–16.0 cm in diameter; sepals 3, obovate, concave, revolute when dry (6.1–)7.0–8.0 × (3.8–)4.0– 4.9 cm; petals 6, white, concave, outer petals narrowly obovate (5.6–)6.2–7.7 × 2.9–3.8 cm, inner petals narrowly obovate to oblanceolate 6.2–6.8 × 2.5–3.0 cm; stamens 92–103, 1.76–2.14 × 0.24–0.42 cm; gynoecium 3.7–4.2 × 2.0– 2.8 cm, rhomboid, glabrous, with persistent styles; fruits 12.2–14.6 × 5.5–6.6 cm, narrowly ovoid to ellipsoid, green to greenish brown, fruit axis (7.7–)8.6–11.0 × 1.6–2.45 cm (1.1–1.4 cm thick at the base), fusiform, with strongly apiculate apex, follicles 22–28, glabrous, abaxially warty, costate, slightly gibbous before dehiscence, the abaxial portion detaches from the fruit axis individually or in pairs, sometimes in masses of several carpels (<8), sometimes remaining attached to the base of the axis, apiculate to truncate; seeds 1.3–1.6 × 1.2 – 1.3 cm, 1.0 cm thick, sarcotesta brilliant red when ripe with dark brown to black testa.

Distribution, phenology and ecology:— Known from three localities in the Chajul Municipality of Quiché, 1255–1560 m in remnant cloud forest. Flowering April–June, fruiting May–November.

Etymology:— Referring to the Department of Quiché, Guatemala, where the species was discovered.

Conservation status:— Known from three localities, and so the extent of occurrence was estimated at 24.9 km ². The area of occupancy is 12 km ² using IUCN recommended grid cell. The reduction of the geographic range was inferred from the fact that the cloud forest remnant habitat of this species are located in the neighbourhood of villages.

The forest is already severely fragmented because of deforestation and land-use change for agricultural and cattle raising, and these forest fragments are at risk of disappearance considering the existing deforestation tendencies in the north of the Quiché Department. The species has a highly fragmented geographic distribution and is associated with a habitat that is continuously being reduced its area and is projected to decline soon. From several known localities and the size of the geographic distribution, it fulfils both B1ab(iii) and B2ab(iii) IUCN (2019) criteria for endangered (EN) species. The species is not protected by the Guatemalan system of protected areas ( CONAP 2011).

Other specimens examined: — GUATEMALA. Quiché: municipality of Chajul, Amacchel , 1431 m, 15°40’N, 91°05’W, 22 Aug 2018 (fr), Tribouillier & Archila MG-071 ( AGUAT) ; 30 Apr 2019 (fl, fr), Tribouillier & Archila MG-072 ( AGUAT) ; 10 May 2019 (fl), Tribouillier & Archila MG-073 ( BIGU) ; 28 Sep 2019 (fr), Tribouillier & Archila MG-074 ( IBUG) ; 10 Nov 2019 (fr), Tribouillier & Archila MG-075 ( BIGU) ; Aldea Chel, 1557 m, 15°40’N, 91°00’W, 1 Sep 2018 (inm. fl), Tribouillier & Archila MG-076 ( BIGU) ; Aldea Santa Clara , 1255 m, 15°43’N, 91°01’W, 13 Apr 2019 (fl, fr), Tribouillier & Archila MG-109 ( BIGU) .

Figures

FIGURE 1. Magnolia quichensis. A. Habit. B. Flower in female phase. C. Flower in male phase. D. Holotype. E. Spathaceous bract. Photographs A–C, E. by Erick Tribouillier; D. by Mario Véliz

FIGURE 2. Magnolia quichensis. A. Developing fruit. B. Mature fruit before dehiscence, C-D. Fruit during dehiscence. E. Seeds after sarcotesta removal. F-G. Fruit axis and carpels without seeds, dorsal and ventral side, showing the axis. Photographs: Erick Tribouillier.

FIGURE 4. Distribution of Magnolia quichensis, M. weerakitana and other Magnolia species from the centre of Magnolia endemism in the Guatemalan north-west-arc.